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GMichael
02-20-2006, 09:05 AM
I have a coworker who came to me this morning with a question. It seems that his old receiver has died and he is looking for a replacement. He claims that his turntable is quad and that his receiver used to reproduce 4 discrete channels.
Will today's multi channel receivers be able to do this for him or is this gone forever?

topspeed
02-20-2006, 09:57 AM
If you believe the manufacturers, then the answer is "Yes." Most claim that their amplifier sections are discrete, although I question how "discrete" it really is if they all share the same power supply, transformer, etc. Meh, symantics. As long as the avr has a phono section, which is hardly a given, he should be fine with a decent unit. He may want to lean towards more mid-fi avr's from Rotel, Arcam, NAD, Cambridge, or B&K, if that is the level he is accustomed to.

SlumpBuster
02-20-2006, 10:17 AM
I would add even more caveats to Topspeeds answers. So many in fact that his "Yes" becomes a "Probably not" depending on the source. If you think we have a lot of formats today, DTS, DD, ES/EX, Prologic II, ect., it is nothing compared to the heyday of quad. Formats were competing and many were incompatible. Many were also dependant on an outboard demodulator.

Here's the thing: If your friend has four RCA outputs (Front right and left, and back right and left), then he sould be able to connect up to any modern reciever or integrated with multichannel inputs. But chances are it won't be processed correctly. The most likely source for this would be reel to reel. I don't know of any turntables that would not need an outboard demodulator. I would almost be certain that your friends turntable only has left and right outputs.

But, the good thing is that there are lots of quad recievers on Ebay, for good prices. Many manufacturers, including Panasonic/Technics prided themselves on receivers that would demodulate or be able to handle any quad source. Here is an auction that I was watching. This is a topnotch quad receiver.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=5866549839&ssPageName=STRK:MEWA:IT

I don't think he should screw around. If he still wants quad, get a quad receiver.

emaidel
02-20-2006, 11:03 AM
He claims that his turntable is quad and that his receiver used to reproduce 4 discrete channels.
Will today's multi channel receivers be able to do this for him or is this gone forever?

The answer to that specific question is an emphatic, "No." Today's 5.1 surround systems, and quadraphonic sound from the 70's have almost nothing in common, except that both provide sound from more than two point sources. Your friend's "quad" turntable is nothing of the sort, but most likely a standard turntable, fitted with a cartridge designed to play old "CD-4" records. It had a two-channel output that had to go into a "demodulator" for the four signals to be separated, and then fed into four different channels of amplification. Most quad receivers had a demodulator already built into them. There never was anything called a "quad turntable."

The other forms of quadraphonic sound (at least on records) were SQ and QS or "Regular Matrix, " or "RM" for short. they didn't require a special cartridge, but had to have their signal fed into a "decoder," and then also into four channels of amplification. Again, receivers had both SQ and RM decoders built into them too, but of widely varying quality and separation. And lastly, there were discrete four channel tapes.

None of the decoding equipment in today's surround receivers properly decodes SQ, QS or anything of the sort, and none have CD-4 demodulators in them either. I suspect also that few have even got phono inputs at all.

They do, however, provide far better isolated sound sources than most quadraphonic formats ever did, and also have center channel outputs (which no quad setup ever had), and provide a subwoofer output too (the term "subwoofer" didn't even exist in quad days.)

I have a 5.1 setup in my living room which came as a "package deal" when I bought my house. Insofar as accuracy and sonic fildelity go, it leaves much to be desired, but when it comes to listening to 5.1 movies, the effect is amazing. It consists of a cheapo JVC receiver with five so-called "discrete" outputs, each capable of 100 watts (I'm not holding my breath on the veracity of that one!), and a sub out. I think it provides a wonderful enhancement to the enjoyment of DVD rentals, nor is there any doubt where the sounds are actually coming from unlike days of quad when isolation of the four channels wasn't always particularly good. Howeverf, it pales in comparison to my far superior 2-channel system which I have elsewhere in my house when it comes to any serious listening.

So, yes, today's surround-sound receivers do a pretty decent job of separating a multitude of different sound sources (front left, front right, rear left, rear right and center), but most of us audio enthusiasts or audiophiles still prefer the "old-fashioned" 2-channel variety for serious listening. And anything labeled "quadraphonic" from the 70's just won't work through today's surround equipment. I may be wrong on this one, but the four discrete outputs from tape sources probably can't be used either, because I don't think today's surround-sound receivers have four separate inputs to accomodate them.

Hope all of that was helpful.

GMichael
02-20-2006, 11:57 AM
Thanks to all. This has been very helpful.
You are right, the turntable is a std one with a quad cart. It only has 2 jacks out that he has going into some sort of decoder before hitting his receiver.
I think he is giving up his quest for quad and will move into the 21st century and get a 5.1 or 7.1 system. His main concern now is getting a center speaker to match his Dahlquist DQ-10's.

SlumpBuster
02-20-2006, 12:16 PM
What a great thread :D. Answers from three people, all pretty knowledgable, going from "Yes" to "Probably not" to "Emphatically No."

GMichael
02-20-2006, 12:32 PM
What a great thread :D. Answers from three people, all pretty knowledgable, going from "Yes" to "Probably not" to "Emphatically No."

What's life without a little rollercoaster ride now and then?

JohnMichael
02-20-2006, 02:55 PM
The answer to that specific question is an emphatic, "No." Today's 5.1 surround systems, and quadraphonic sound from the 70's have almost nothing in common, except that both provide sound from more than two point sources. Your friend's "quad" turntable is nothing of the sort, but most likely a standard turntable, fitted with a cartridge designed to play old "CD-4" records. It had a two-channel output that had to go into a "demodulator" for the four signals to be separated, and then fed into four different channels of amplification. Most quad receivers had a demodulator already built into them. There never was anything called a "quad turntable."

The other forms of quadraphonic sound (at least on records) were SQ and QS or "Regular Matrix, " or "RM" for short. they didn't require a special cartridge, but had to have their signal fed into a "decoder," and then also into four channels of amplification. Again, receivers had both SQ and RM decoders built into them too, but of widely varying quality and separation. And lastly, there were discrete four channel tapes.

None of the decoding equipment in today's surround receivers properly decodes SQ, QS or anything of the sort, and none have CD-4 demodulators in them either. I suspect also that few have even got phono inputs at all.

They do, however, provide far better isolated sound sources than most quadraphonic formats ever did, and also have center channel outputs (which no quad setup ever had), and provide a subwoofer output too (the term "subwoofer" didn't even exist in quad days.)

I have a 5.1 setup in my living room which came as a "package deal" when I bought my house. Insofar as accuracy and sonic fildelity go, it leaves much to be desired, but when it comes to listening to 5.1 movies, the effect is amazing. It consists of a cheapo JVC receiver with five so-called "discrete" outputs, each capable of 100 watts (I'm not holding my breath on the veracity of that one!), and a sub out. I think it provides a wonderful enhancement to the enjoyment of DVD rentals, nor is there any doubt where the sounds are actually coming from unlike days of quad when isolation of the four channels wasn't always particularly good. Howeverf, it pales in comparison to my far superior 2-channel system which I have elsewhere in my house when it comes to any serious listening.

So, yes, today's surround-sound receivers do a pretty decent job of separating a multitude of different sound sources (front left, front right, rear left, rear right and center), but most of us audio enthusiasts or audiophiles still prefer the "old-fashioned" 2-channel variety for serious listening. And anything labeled "quadraphonic" from the 70's just won't work through today's surround equipment. I may be wrong on this one, but the four discrete outputs from tape sources probably can't be used either, because I don't think today's surround-sound receivers have four separate inputs to accomodate them.

Hope all of that was helpful.

I agree with emaidel regarding turntables. There was never a quad turntable but Audio Technica created the Shibata stylus to track ultra high frequencies that were later demodulated along with the standard frequencies into the four channels.

Woochifer
02-20-2006, 06:35 PM
Actually, a Dolby Pro Logic decoder should be able to extract some surround information from a matrix-encoded LP. The only formats that would clearly not work are the discrete formats that required the demodulators. I believe that there are also external quad decoders that work with several quad formats, and if they provide a four channel output, then that would work with any multichannel receiver that has a multichannel analog input (and that would include just about all Dolby Digital-equipped receivers, as well as a lot of Pro Logic receivers).

Another thing to consider is that some quad recordings from the 70s have been reissued on DVD-A and SACD. The advantage here obviously is that these formats use high resolution discrete channels, rather than the matrixed or modulated signals of quad. I have a couple of the Vox quad recordings on SACD (Mobile Fidelity's reissues of Vox's Gershwin and Ravel recordings), and they sound incredible in how they convey the hall ambience and meld with the front soundstage.


So, yes, today's surround-sound receivers do a pretty decent job of separating a multitude of different sound sources (front left, front right, rear left, rear right and center), but most of us audio enthusiasts or audiophiles still prefer the "old-fashioned" 2-channel variety for serious listening. And anything labeled "quadraphonic" from the 70's just won't work through today's surround equipment. I may be wrong on this one, but the four discrete outputs from tape sources probably can't be used either, because I don't think today's surround-sound receivers have four separate inputs to accomodate them.

As mentioned above, most multichannel receivers made within the last 10 years (dating back to when Pro Logic receivers were labeled "Dolby Digital ready" so that they would work with the first generation of external AC-3 decoders) will accept a six-channel analog input.

On your other point, I think that multichannel is readily adaptable to "serious" listening if the front end equipment and speakers are close to the caliber of a good two-channel system. If you're comparing an entry level HT receiver with in-wall speakers, against a higher level two-channel setup, then it's not really a comparable listening. With SACD and DVD-A, you're looking at formats that have higher resolution than CD AND are capable of discrete six-channel output. Recording engineers are only beginning to scratch the surface of what's possible with more than two channels, and there are already plenty of compelling examples of multichannel recordings that far outpace their two-channel versions.